The cardan shaft is a pipe through which the torque developed by the engine is transmitted from the transfer case to the final drive differential. Both ends of the shaft are equipped with universal (cardan) hinges.
At the front, the cardan shaft is equipped with a sliding clutch with a forked clamp of the cardan joint at the end. The clutch fits into the transmission extension housing, which provides the transmission line with the required freedom of movement in the longitudinal direction, compensating for transmission shifts that inevitably occur during vehicle movement. The tightness of the fitting of the coupling in the extension housing is provided by an oil seal, which, in the event of a leak, must be replaced.
Each of the cardan shafts is attached to the transfer case by means of a connecting flange. After removing the cardan shaft, the corresponding flange can be dismantled from the box in order to check the condition and replace the oil seals. Each of the flanges is equipped with two seals - one is installed between the flange and the box crankcase, the second (smaller) seated directly inside the flange.
Cardan shafts require minimal attention. The hinges are packed with grease once and in case of failure they are replaced as an assembly. Replacement of hinges is made on the shaft removed from the car.
Due to the nature of its purpose, the cardan shaft requires good balancing, which implies the need to periodically clean it from adhering mud deposits, try to inspect the shafts every time the car is raised above the ground for any reason. Check that the balancing weights are in place and securely fixed. Remember that turning the shaft 180°during installation inevitably leads to imbalance.
Violation of the proper functioning of the cardan shaft is usually accompanied by characteristic sounds and an increase in the level of vibration when the car is moving (see the section on diagnosing malfunctions of vehicle components and systems during Administered to this guide).